The invention relates to a device and a method for the transmission of data between a central unit (master) and at least one functional unit (slave) via at least two lines, each functional unit being connected to at least one sensor or actuator.
Such a device is generally known, for example, as a bus system under the designation INTERBUS-S, and is also standardized. This bus system is designed such that it operates like a shift register. This results in the advantage that the individual subscribers need not be identified by addresses. On the other hand, the individual subscribers or the individual functional units, and thus the actuators and sensors as well, cannot be selected individually by the central unit.
Other devices of this type are known in which the addresses must be programmed in advance or which do not require any addresses at all as the data are intrinsically received selectively by the subscribers. However, such systems can be used only in specific, given circumstances.
It is therefore the object of the invention to provide a method and a device which allow the interchange of data between a central unit and individual subscribers objectively in a cost-effective manner, it being possible to reassign the selection of the subscribers repeatedly and in a simple manner.